Scala/Spark Ordering on multiple dimensions with reverse on specific one -


i order exemple 2d array or rdd follow :

val = array((1,1),(1,2),(1,3),(2,1),(2,2),(2,3))

to obtain ascending sort on d1 , descending 1 on d2 :

val b = array((1,3),(1,2),(1,1),(2,3),(2,2),(2,1))

unfortunately when apply reverse in ordering apply on dimensions

a.sortby( x=> (x._1,x._2) )(ordering[(int,int)].reverse.on(x=> (x._1,x._2))) array((2,3), (2,2), (2,1), (1,3), (1,2), (1,1))

so able sort on multiple dimension choising on 1 need reverse sorting.

this post contains answear scala idiom ordering multiple criteria

val ord1 = ordering.by{ x:int => x } val ord2 = ordering.by{ x:int => x }.reverse val multord = ordering.by{ x:(int,int) => x }(ordering.tuple2(ord1,ord2)) a.sortby( identity )(multord) array((1,3),(1,2),(1,1),(2,3),(2,2),(2,1))

hope can help


Comments

Post a Comment

Popular posts from this blog

javascript - Confirm a form & display message if form is valid with JQuery -

i'm developing django application , use javascript in order improve website. i have form , display 2 things : confirm form before submit if form submitted, display message : 'form saved' it's first time i'm using js , need make process. this code : <form class = "form" method='post' action=''> {% csrf_token %} <br></br> {{ form.as_p}} <br></br> <button type="submit">valider</button> </form> <script> $('#form').submit(function() { var c = confirm("click ok continue?"); return c; //you can return c because true or false }); </script> and if form valid , saved : <script type="text/javascript" > $(document).on('valider', 'form.form', function(form) { var $form = $(form); $.ajax({ ...
Read more

Retrieving ETA (estimated time of arrival) with Google Distance Matrix API and public transit as transport mode -

Image
is possible retrieve eta google's distancematrix api (or alternative api). fyi, eta different duration, when using public transport. following example clarify request. when leave on friday @ 8.15 i'll able catch train @ 8.30 , arrive @ 9.00 am. google says duration 30 minutes. however, when leave on saturday @ 8.15 i'll able catch first train @ 9.00 , arrive @ 9.30 am. google still says duration 30 minutes, means ignore delay. google map supports functionality there api around giving me eta instead of duration. can see, distance-matrix' response no good. clarifying question little. eta estimated time of arrival , it's clear user wants know entire duration of transport (including waiting time public transport).
Read more

android - ConstraintLayout: Realign baseline constraint in case if dependent view visibility was set to GONE -

Image
is there way realign baseline constraint textview in case if dependent view visibility set gone? my layout code: <android.support.constraint.constraintlayout android:layout_width="match_parent" android:layout_height="wrap_content"> <textview android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="test title" android:textcolor="@color/black" android:textsize="24sp" app:layout_constraintleft_toleftof="parent" app:layout_constraintright_torightof="parent"/> <textview android:id="@+id/subtitle1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="subtitle 1" android:textsize="11sp" app:layout_constraintb...
Read more